The vibroscanning method for the measurement of micro-hole profiles

In this paper, we present technologies for measuring inner dimensions of small holes. In the first method with a single probe system, the electrical contact between a vibrating probe and the inner surface of a hole is detected and the duty factor of the contact is measured. Through controlled scanning by a probe with a constant duty factor, data on the ups and downs of the surface profile are obtained. To characterize inside profiles of micro-holes regardless of materials, we developed a new technology with a twin-probe system. With a silicon-based micro-twin probe 3 mm in length, a micro-hole with a diameter of around 125 mu m was measured and the estimated imprecision of measurement on this set-up is smaller than 0.5 mu m.